[PATCH] ARM: bootm: recalculate decompression space

[Sascha Hauer]

On Tue, Jul 05, 2016 at 11:47:08AM +0200, Alexander Kurz wrote:
> Hi Stefan,
> FYI, I just got a compiler warning obviously related to your patch
> On Fri Jul 1 07:48:39 PDT 2016, Stefan Müller-Klieser wrote:
> 
> > diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
> > index 803aa94..be1259b 100644
> > --- a/arch/arm/lib/bootm.c
> > +++ b/arch/arm/lib/bootm.c
> > @@ -81,10 +81,15 @@ static int get_kernel_addresses(size_t image_size,
> >  		return ret;
> >  
> >  	/*
> > -	 * We don't know the exact decompressed size so just use a 
> > conservative
> > -	 * default of 4 times the size of the compressed image.
> > +	 * The kernel documentation "Documentation/arm/Booting" advises
> > +	 * to place the compressed image outside of the lowest 32 MiB to
> > +	 * avoid relocation. We should do this if we have at least 64 MiB
> > +	 * of ram. If we have less space, we assume a maximum
> > +	 * compression factor of 5.
> >  	 */
> > -	image_decomp_size = PAGE_ALIGN(image_size * 4);
> > +	image_decomp_size = PAGE_ALIGN(image_size * 5);
> > +	if (mem_size >= SZ_64M)
> > +		image_decomp_size = max(image_decomp_size, SZ_32M);
> >  
> >  	/*
> >  	 * By default put oftree/initrd close behind compressed kernel 
> > image to
> 
> this one:
> >   CC      arch/arm/lib/bootm.o
> > In file included from include/common.h:30:0,
> >                  from arch/arm/lib/bootm.c:2:
> > arch/arm/lib/bootm.c: In function 'get_kernel_addresses':
> > include/linux/kernel.h:110:17: warning: comparison of distinct pointer 
> > types lacks a cast
> >   (void) (&_max1 == &_max2);  \

I get that aswell. Will change to:

	max_t(size_t, image_decomp_size, SZ_32M);

Sascha


-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |